Meaning of Idiom 'Run Interference'

To run interference is to help someone accomplish something by dealing with potential problems so as to eliminate encumbrances or distractions; to intervene in order to help another person.

Usage

"Tod, my son's school just called. He's sick and I need to pick him up. Can you run interference with the boss for me while I'm gone?"

"You just concentrate on the case," said Erin, "I'll run interference with the press."

Origin

Used since the mid-1900's.

In American football, to run interference is to deploy an array of blockers in front a ball carrier to help clear a path by blocking the opposing players and shoving them out of the way, thus removing the "interference" from the field so that the ball carrier can score a goal. This activity was legalized in American football in 1889. Because of the outrageous tactics first used, several fatalities happened on the field. After the more lethal forms of running interference were banned, to dissociate the activity from its negative past, it became known as blocking, but this change did not occur before running interference began to be used figuratively to mean helping to clear the way for someone else to accomplish something. (The Field Guide to Sports Metaphors: A Compendium of Competitive Words and Idioms)